Audible Warning Device Control Module: Description and Operation

For additional information on the Central Timer Module, refer to Powertrain Management / Computers and Control Systems / Body Control Module. Body Control Module

CENTRAL TIMER MODULE
The Durango (DN) utilizes a Central Timer Module (CTM). This system is available in a Base or Highline configuration.

The CTM performs most of the typical functions a Body Control Module would perform.

The Base and Highline CTM provides the following features:
- Battery Saver Functions For Exterior and Interior Lamps
- Cargo Lamps
- Chime Warning
- Courtesy Lamps
- Dome Lamps
- Dome Defeat
- Door Ajar Switch Status
- Fog Lamps
- Head Lamp Time Delay
- Intermittent Wiper Controls
- Low and High Beam Head Lamps
- Optical Horn
- Park Lamps

Additional features of Highline CTM
- Central Locking (VTSS)
- Door Lock Inhibit
- Driver Door Unlock
- Enhanced Accident Response
- Power Door Locks
- Remote Radio
- Remote Keyless Entry
- Vehicle Theft Alarm (VTSS)

Fig. 1 Central Timer Module:

The Central Timer Module is located behind the left side kick panel. It contains 26-way, 16-way and 12-way connectors.

The high-line Central Timer Module (CTM) can also control some features of the audio system when the vehicle is equipped with the optional RAZ radio receiver and remote radio switches. A high-line CTM is used on high-line versions of this vehicle. The CTM combines the functions of a chime/buzzer module, an intermittent wipe module, an illuminated entry module, a remote keyless entry module, and a vehicle theft security system module in a single unit.

The high-line CTM also controls and integrates many of the additional electronic functions and features included on models with this option. The RAZ radio receiver with a remote radio switch option is one of the features that the CTM controls. The CTM is programmed to send switch status messages over the J185O data bus to control the volume, seek, and pre-set station advance functions of the RAZ radio receiver. The CTM monitors the status of the remote radio switches located on the steering wheel through a hard wired circuit. The CTM then sends the proper switch status messages to the radio receiver. The electronic circuitry within the radio receiver responds to the switch status messages it receives by adjusting the radio settings as requested.

In addition, radio receivers connected to the J1850 data bus have several audio system functions that can be diagnosed using a DRB scan tool. Refer to the proper Diagnostic Procedures for more information on DRB testing of the audio systems.

Two versions of the Central Timer Module (CTM) are available on this vehicle, a base version and a high-line version. Whichever version of the CTM the vehicle is equipped with, it is concealed behind the trim on the left cowl side inner panel below the instrument panel, where it is secured with three screws. The CTM is enclosed in a molded plastic housing with three integral external connector receptacles that connect it to the vehicle electrical system through one take out and connector of the body wire harness, and two take outs and connectors of the instrument panel wire harness. The base version of the CTM is used on base models of this vehicle. These base models are not equipped with the optional power lock system, the Remote Keyless Entry (RKE) system, the rear wiper system, the Vehicle Theft Security System (VTSS), or the remote radio controls. The high-line version of the CTM is used on high-line vehicles that are equipped with one or more of those options not found on base models.

The CTM utilizes integrated circuitry and information carried on the Programmable Communications Interface (PCI) data bus network along with many hard wired inputs to monitor many sensor and switch inputs throughout the vehicle. In response to those inputs, the internal circuitry and programming of the CTM allow it to supply the vehicle occupants with audible and visual information, and to control and integrate many electronic functions and features of the vehicle through both hard wired outputs and the transmission of electronic message outputs to other electronic modules in the vehicle over the PCI data bus.
The features that the CTM supports or controls include the following:
- Automatic Door Lock - The high-line CTM provides an automatic door lock feature (also known as rolling door locks). This is a programmable feature.
- Battery Protection - The CTM provides a battery saver feature that performs timed load shedding whenever courtesy, reading, visor vanity, center console, glove box, or any exterior lamps are left on with the ignition switch in the OFF position.
- Central Locking - The high-line CTM on vehicles equipped with the optional Vehicle Theft Security System (VTSS) includes a central locking/ unlocking feature.
- Chimes - All versions of the CTM provide chime service and beep request service through an integral chime tone generator.
- Door Lock Inhibit - The high-line CTM provides a power door lock inhibit feature.
- Enhanced Accident Response - The high-line CTM provides an optional enhanced accident response feature. This is a programmable feature.
- Exterior Light Features - The CTM provides control of park lamps, fog lamps, and headlamps. This includes support for optical horn (also known as flash-to-pass), headlamp time delay, daytime running lamps (DRL - Canada only), and battery saver features.
- Interior Light Features - The CTM provides control of courtesy lamps, dome lamps, and the lift- gate lamp. This includes support for a timed illuminated entry with fade-to-OFF, interior lighting delay, courtesy illumination defeat, and battery saver features.
- Intermittent Wipe Control - The CTM provides control of the intermittent wipe delay, and wipe-after-wash features for the front wiper and washer system. The high-line CTM also provides these same features for the optional rear wiper and washer system.
- Panic Mode - The high-line CTM provides support for the optional RKE system panic mode including horn chirp, headlamp flash, and park lamp flash features.
- Power Lock Control - The high-line CTM provides the optional power lock system features, including support for the automatic door lock and door lock inhibit modes.
- Programmable Features - The CTM provides support for certain programmable features.
- Remote Keyless Entry - The high-line CTM provides the optional Remote Keyless Entry (RKE) system features, including support for the RKE Lock (with optional horn chirp and park lamps flash), Unlock (with optional park lamps flash, driver-door- only unlock, and unlock-all-doors), Panic, and illuminated entry modes, as well as the ability to be programmed to recognize up to four RKE transmitters. The RKE horn chirp, park lamps flash, driver- door-only unlock, and unlock-all-doors features are programmable.
- Remote Radio Switch Interface - The high- line CTM monitors and transmits the status of the optional remote radio switches on the steering wheel.
- Speed Sensitive Intermittent Wipe Control - The CTM provides a speed sensitive front intermittent wipe feature.
- Vehicle Theft Security System - The high-line CTM provides control of the optional Vehicle Theft Security System (VTSS) features, including support for the central locking/unlocking mode and control of the Security indicator in the instrument cluster.

Hard wired circuitry connects the CTM to the electrical system of the vehicle. These hard wired circuits are integral to several wire harnesses, which are routed throughout the vehicle and retained by many different methods. These circuits may be connected to each other, to the vehicle electrical system and to the CTM through the use of a combination of soldered splices, splice block connectors, and many different types of wire harness terminal connectors and insulators.

All versions of the CTM for this model are serviced only as a complete unit. Many of the electronic features in the vehicle controlled or supported by the CTM are programmable using the DRB III scan tool. In addition, the CTM software is Flash compatible, which means it can be reprogrammed using Flash reprogramming procedures. However, if any of the CTM hardware components are damaged or faulty, the entire CTM unit must be replaced. The hard wired inputs or outputs of all CTM versions can be diagnosed using conventional diagnostic tools and methods; however, for diagnosis of the CTM or the PCI data bus, the use of a DRB III scan tool is required. Refer to the appropriate diagnostic information.

The microprocessor-based Central Timer Module (CTM) monitors many hard wired switch and sensor inputs as well as those resources it shares with other electronic modules in the vehicle through its communication over the Programmable Communications Interface (PCI) data bus network. The internal programming and all of these inputs allow the CTM microprocessor to determine the tasks it needs to perform and their priorities, as well as both the standard and optional features that it should provide. The CTM programming then performs those tasks and provides those features through both PCI data bus communication with other electronic modules and through hard wired outputs through a number of driver circuits, relays, and actuators. These outputs allow the CTM the ability to control numerous accessory systems in the vehicle.

The CTM operates on battery current received through two fuses in the Junction Block (JB) on two non-switched fused B(+) circuits, a fused ignition switch output (run-start) circuit, and a fused ignition switch output (run-acc) circuit. This arrangement allows the CTM to provide some features regardless of the ignition switch position, while other features will operate only with the ignition switch in the Accessory, ON, and/or Start positions. The CTM receives ground through its connector and take out of the instrument panel wire harness on three separate ground circuits. Two of these circuits are grounded through a take out of the instrument panel wire harness with an eyelet terminal connector that is secured by a nut to a ground stud on the left inner cowl side panel near the CTM, while the third circuit is grounded through a take out of the instrument panel wire harness with an eyelet terminal connector that is secured by a ground screw to the left side of the floor panel transmission tunnel near the Airbag Control Module (ACM).

The CTM monitors its own internal circuitry as well as many of its input and output circuits, and will store a Diagnostic Trouble Code (DTC) in electronic memory for any failure it detects. These DTCs can be retrieved and diagnosed using a DRB III scan tool. Refer to the appropriate diagnostic information.

Hard Wired Inputs
The hard wired inputs to the CTM include the following:
- Courtesy lamp switch sense
- Cylinder lock switch sense - high line with VTSS only
- Driver door ajar switch sense
- Driver door switch mux - high line with power locks only
- Fog lamp switch sense
- Front washer pump/motor control
- Front wiper park switch sense
- Fused B(+) (two circuits)
- Fused ignition switch output (run-acc)
- Fused ignition switch output (run-start)
- Ground (three circuits)
- Headlamp switch off sense
- High beam switch output
- Interior lamp defeat
- Intermittent front wiper mode sense
- Intermittent front wiper switch signal
- Key-in ignition switch sense
- Liftgate ajar switch sense
- Low beam switch output
- Park brake switch sense
- Park lamp switch sense
- Passenger door ajar switch sense
- Passenger door switch mux - high line with power locks only
- PCI bus circuit
- Radio control mux - high-line with remote radio switches only
- Washer switch sense
- Wiper park switch sense
- Wiper switch mode sense
- Wiper switch mode signal

Hard Wired Outputs
The hard wired outputs of the CTM include the following:
- Courtesy lamp driver
- Door lock relay output - high-line with power locks only
- Door unlock relay output - high-line with power locks only
- Driver door unlock relay output - high-line with power locks only
- Fog lamp relay control - with fog lamps only
- Front washer pump/motor control
- Front wiper park switch sense
- Front wiper relay control
- Glove box lamp driver
- High beam indicator driver
- Horn relay control - high-line with power locks only
- Interior lamp driver
- Left high beam driver
- Left low beam driver
- Park lamp relay control
- Rear wiper park switch sense - high line with rear wiper and washer system only
- Rear wiper relay control - high line with rear wiper and washer system only
- Right high beam driver
- Right low beam driver
- VTSS indicator driver - high-line with VTSS only

Messaging
The CTM uses the following messages received from other electronic modules over the PCI data bus:
- Airbag Deploy (ACM)
- Beep request (CMTC)
- Charging System Failure (PCM)
- Chime request (EMIC)
- Engine RPM (PCM)
- OK to Arm VTSS (PCM)
- Rear Washer Status (Heater-A/C Control)
- Rear Wiper Status (Heater-A/C Control)
- Security indicator request (SKIM)
- System Voltage (PCM)
- Valid/Invalid Key (SKIM)
- Vehicle Distance (PCM)
- Vehicle Speed (PCM)
- Voltage Fault (PCM)

The CTM provides the following messages to other electronic modules over the PCI data bus:
- Door Ajar Status (EMIC)
- Liftgate Ajar Status (EMIC)
- Park Brake Status (CAB, EMIC, TCM)
- Radio Mode (Radio)
- Radio Preset Scan (Radio)
- Radio Seek Down (Radio)
- Radio Seek Up (Radio)
- Radio Volume Down (Radio)
- Radio Volume Up (Radio)